When I was 16, as a student at a Christian school I had a conversation with my mother about what I called common human nature. She told me that there was no such thing, and that she never wanted to hurt anyone.
I realized that she was right.
At this point in my life I have no ill will toward anyone. Clearly there are times when people need to be faced with consequences of their actions, and clearly there are times when people need to act in wiser ways. That does not mean that they have to suffer. It means that they need to make better decisions.
In most cases, when someone is doing the wrong thing, it should be possible to convince him that he is doing the wrong thing. When their children do things wrong, many parents punish them when what they really need to do is explain to the child why what the child is doing is wrong. In most cases the child will understand and react accordingly.
The suffering is not the point. Wisdom is. Sometimes it takes suffering to achieve wisdom, and sometimes it doesn’t. My daughter hasn’t had much suffering in her life, but she has always been very wise. Her first social interaction was coming up to another little girl and hugging her. When I talked to her about yuckie people she said, “There are no yuckie people.” Here is someone who has achieved wisdom without suffering. Whereas there are many people who suffer who aren’t wise at all.
Does suffering lead to wisdom? Sometimes it does and sometimes it doesn’t. Once again, there are times when people need to be faced with consequences of their actions; but in many other cases it is possible to achieve the same result with persuasion. Suffering, in itself, should not be encouraged. Wisdom should be. And that can be achieved with or without suffering.